1. Field of the Invention
The present invention relates to an apparatus and method for controlling an actuator that controls the opening and closing of an intake valve. More particularly, it relates to an apparatus and method that controls the actuator such that the intake valve opens and closes depending on the operating conditions of an engine. The present invention makes it possible to simplify the actuator structure and, thus, reduces design costs associated therewith, and further improves the control precision of the actuator.
2. Description of the Related Art
Recently, various efforts have been made to improve the power and efficiency of a vehicle engine. These efforts have included the attempt to improve intake efficiency by adjusting the shape of an intake manifold and by controlling the timing at which an intake valve opens and closes.
FIG. 1 illustrates an actuator installed in the intake manifold to control the timing at which the intake valve opens and closes. As shown, the actuator includes a casing 100 that is fastened to the intake manifold. The casing houses a drive motor 2 provided with a pinion gear 24 on a drive shaft, a two-step gear part 4 including a plurality of gear parts and having a shaft coupled to the inside of the casing 100, a valve gear part 6 engaged with the two-step gear part 4 and provided with a valve shaft 400 as a central shaft, and a sensor part 8 installed in a portion of the valve gear part 6 and configured to sense the angle of rotation of the valve shaft 400. Here, the sensor part 8 is installed within the casing 100 to correspond to a magnet 64, and is implemented using a hall element 82.
In particular, after a displacement between the magnetic fields of the hall element 82 and the magnetic fields of the magnet 64 in the valve gear part, a control unit calculates the displacement. Based on the calculated displacement, the control unit determines whether to drive the drive motor 2 and, if so, in which direction the driver motor 2 is to be driven.
However, while the various components of such an actuator, such as a rotary magnet and a sensor, generate linear outputs which increases resolution (precision), they are relatively expensive.
On the other hand, while relatively inexpensive elements, such as a hall element, can be used, the resolution (precision) of the resulting products may be deteriorated.
The foregoing is intended merely to aid in the better understanding of the background of the present invention, and is not intended to mean that the present invention falls within the purview of the related art that is already known to those skilled in the art.